Rheostatic motor controller



Oct. 7, 1930. G. o.v wsLMs v '1,777,988

RHEOSTATIC MOTOR CONTROLLER Filed Deo, 27, 1926 2 Sheets-Sheet 1 y WWW.

ATTORNEY Oct. 7, 1930. G. o. wlLMs '1;777988 RHEOSTATIC MOTOR CONTROLLER Filed Deo. 27, 1925' 2 Shoots-Sheet 2 INVENTQR @QM/aww D X BY. M l m 9V ATTORNEY Patentedoa. 7, 1930 UNITED l STATESl PATENT OFFICE GUSTAV 0. WILMSfOF MILWAUKEE,` WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS,

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T RELIANCE COMPANY, 0F WILMINGTON, DELAWARE, A CORPORATION OF :BELA-4 nnnosrarrcmpron CONTROLLER Application led December 27, 1926, Serial No, 157,157, and in Great Britain December 28, 1925.

. The invention yrelates to a rheostatic motor controller.

The articular rheostaticmotor controller to w ich the invention applies employs-a carbon disk or other compressible resistor having the pressure thereon controlled by a pivoted lever actuator.

' Such a controller, as itl existed prior to the invention set forth herein, was inca- 110 pable of giving a gradual and controllable variation in resistance above a low and narrow range, as its gradual and controllable variation. in resistance depended upon its resistor being compressible and having a l5 high pressure varied thereon. Accordingly, it was not suitable orsucient to be employed to control fractional horsepower electric motors or for other puroses which require a gradual and controliilble variation in resistancethrough a high and wide range; h rlhe invention has as'its object/to provide la carbon disk controller in which a gradual and controllable-variation in resistance may be obtained through a high and wide range.

Another object is to provide a carbon disk f eontrolleriin which a small resistor will give a gradual and controllable variation in re sistance through a high and wide range. Another Objectis to provide a small and compact motor controller for fractional horsepower motors and other purposes which require a gradual and controllable variav tion in resistance through a high and wide range.

According to the present invention, a pivotedlever actuatorhaving a spring to enable its lever to be given a gradual moveiment and retained in any intermediate posi-Y o tion vis employed to vary the pressure upon a carbon disk or other compressible resistor through a low tension spring proportioned to vary a low pressure'upon the resistor and allow the lever to have a wide and substanf a5 tialmovement in varying the low pressure and therebyobtain a gradual and control- .lable variation in ahigh resistance through a wide range above the normal gradual and controllable variation iii a low resistance obtainable by variations in a high pressure upon the resistor.

The invention which is herein set forth Y provides a rheostatic' motor controller by which a fractional horsepower electric motor may be controlled to obtain a Wide and gradual variation in its speed from a low Y speed to a high speed, but such controller may be employed for various other purposes. rihe present application is a continuation yof co-pending applications otapplicant Seytwo motor controllers in which the invention is employed, and the views therein are as follows:

Fig. 1 is a sectional side view of a controller in which the actuator is provided with a treadle for operating it by the toot;

Fig. 2 is a sectional plan view on the line 2 2 of Fig; 1; Y

Fig. 3 is a sectional end View on the line 3-3 of Fig. 1;

Figf is a sectional plan view of a controller in which the actuator is provided with a lever'or operating it by the knee;

Fig. 5 is a sectional side view on the line 5 5 of Fig. li;

Fig. 6 is a iront end view;

Fig. 7 is a sectional end view on the line 7 7 of Fig. Li; and

Fig. 8 is a rear end view.

oatroller, Figa. to 3 spring 2 to apply pressure to the resistors and control the resistance thereof, a pivoted lever 'actuator 3 to deflect the low tension spring .wide range, but its tension and pressure is always low.

Accordingly, it allows the actuator lever to be moved through a wide range in varying the resistance and enables the resistance to be 'ven a ygradual and controllable variation and accurate adjustment throughout a high I and wide range above the normal gradual and .and this spring,

controllable variation in a low resistance obtainable by yariation in a high pressure upon the resistor.

If the pressure were applied to the resistors directly from the. actuator or through a high tension spring, as in the previous carbon disk controllers, the resistance would vary quickly and aburptly above a low narrow range in which the resistor itself naturally and inherently gradually varies its resistance, and further, the actuator would have a very limited movement and the resistance -could not be gradually varied through a wide range.

lThe resistors bear. against stationary terminals 7 which are fastened to the casing and provided with binding screws 8. The insulating casing is removably mounted within a frame or casing 9 which has its top provided with lugs 10 to support a pivot pin 11 for the actuator.

The actuator is Kprovided with a pedal or treadle for operating it by the foot.

Its movement is controlled by the spring 4, which in this controller is a high tension spring, has sufficient reaction to enable the operator to move the" actuator gradually and readily hold it in any intermediate position. e

The actuator and the resistor spring are connected by a connecting or pull rod 12. c

The resistor spring is arranged upon the pull rod between a head 13 and the yoke 6, and the rod is connected to the actuator by a cross-pin 14 arranged in slots therein. I

The yoke 6 is free to tilt upon the connect- .ing rod to equalize the pressure upon, the reand it is normally retracted from the resistors by a return s ring.15 which bears The return spring acts in opposition to the istor'spring upon the yoke16 and thereby lessens thepressure exerted by the resistor c5 spring upon the resistors.

"`itial resistance of the resistors,

`be readily accomplished by applying pressure y lThe pull-rod is threaded into the cross-pin and maybe turned to adjustr the positionof the yoke.y

When the actuator is in its initial position, i

the circuit through the resistors is opened by the yoke'or bridge 6.

When it is moved to operate the controller, the yoke or bridge engages the resistors and then current ows through the resistors from controller, Figs. .1. to 8 The controller in Figs. 4 to 8 operates upon the same principle as ythe controller which has already been explained.

It is provided with two resistors 16' arranged parallel toeach other within an insulating casing 17.

The insulating casing is removably kfastened upon a base or frame 18 having a bracky Theresistors are arranged between movable studs or plungers 2O and stationary terminals 21.

The stationary terminals are electrically connected to contact plates 22 having binding screws 23 and the same are provided with ferrules 24 by which thecontact plates are fastened in place.

The plungers are held against the resistorsl by adjusting plates 25 which are fastened to the casing by screws 26.

-These plates may be bent to adjust the inand that may to the resistors by an instrument inserted through the ferrules of the stationary terminals.

The pressure upon the resistors is `con-` trolled and varied by a flat low tension resistor spring 27 mounted upon connecting or pull-rod 28.

When the resistor spring is deflected, to apply its maximum pressure, it engages a supplemental flat spring plate 29 which applies additional pressure to further reduce the resistance.

The resistor spring isretracted from the a return spring 30v arranged' plungers by upon the connecting rod between the resistor spring and the casing.

The vconnecting rod carries the guide -31 which arranged between ways 32 on the casing.

ico

vary the resistance thereof.

When the resistancel has been reduced to its 'working limit, the resistors are removed" `into engagement with a stationary contact 34 by the guide 31.

The switch is connected to one stationary terminal and the stationary contact to the other stationary terminal, and they are fastened to the casing by the ferrules of these terminals.

The particular actuator illustrated in Figures 4 to 8 is not claimed as a part of the invention set forth herein and it is disclosed in Chason Patent No. 1,643,292, September 27', 1927.

This actuator is provided with a pivoted crank lever 35, a cam 36 andan operating lever 37. l

Thecrank lever is pivotally mounted upon a post or pin 38 carried by the base or frame 18. i

The connecting 'rod is connected to the crank lever by an insulating nut .39 which has this rod threaded into its. shank 40.

The nut is held from turning by engagement with a lock or lug 41 formed on the crank lever.

The resistor spring may yhave its initial position adjusted by removing the nut from engagement with its lock and then turning it upon the connecting rod.

The cam 36 is carried in a shaft 42 which turns in a bearing '43 upon the bracket 19.

The. actuator has its movement controlled by an actuator spring y44. f

' This spring is arranged betweenl a seat or lug1 45 and the cam.

' he operatin arm is detachably connected to the cam sha by a. coupling ring 46 which is fastened to the shaft by a set screw 47 and provided with a hook48 which engages another hook 49 upon the operating arm.

When the controller is in operation to vary the resistance, the resistor spring 27 engages the resistors and connects the'same in circuit in series, vas in the other controller.

The operating lever 37, through the cam 36,.crank lever 35 and connecting rod 28, operates the resistor s ring 27 `to vary the pressure upon the -resistors and gradually When the resistance has been reduced lto its working limit, the resistors are removed from circuit by the short-circuiting ,switch 33.

. If the controller in Figs. 1 to 4 be provided with a low tension spring of such capacity as to d'eiect about .O2 inches to .20 inches in varying a pressure ofthe order of .10 to .50'lbs. a gradual and controllable variation in resistance of the order of 150 ohms to 50 ohms may be obtained and if the controller in Figs.-4 to 8 be provided with a low tension spring of such `capacity as-deflects about .04 to2() inches in varying a pressure A,creased by pressure.

of the order of .03 to .25 lbs. a gradual and controllable variation in resistance of the order of 400 ohms to 100 ohms may be obtained.

' Of course, the capacity of a low tension spring may be varied according to the range of gradual and'controllable variations in resistance required.

. The invention set forth herein provides a y' controller which is simple, compact and etilcient, and which may be employed for purposes in practice for which the previous carbon disk controllers were -not suitable or sufficient.

The invention is hereby claimed as follows:

' 1. A rheostatic controller comprising in combination a carbon disk resistor, an actuator having a ivoted operating lever and a spring to enable said lever 'to be given a gradual movement and retained in any lntermediate position, and means forlvarying a low pressure uponsaid resistor and allowv ing said lever to have a wide or substantial gradual movement land retained in any inter-` mediate position and means actuated by said actuator to varya low pressure upon said resistor by a low-tension spring proportioned to allow said lever to have a wide or substantial movement in varyin said low pressure and-thereby enable a gra ual variation in resistance to be obtained throughout a Wide range above the normal gradual variation in a low resistance obtainable by variations in 'a high pressure upon said resistor.

3. A rheostatic controller comprising in combination a carbon disk resistor, an actuator having a pivoted operating lever and a spring to enable said lever to be given a gradual movement and retained in anyl intermediate position, means actuated by said actuatory b e obtained throughout a wide rangel above the normal gradual variation in a low resisby enable a gradual variation in resistance to tance obtainable by variations in a high pres- I 'sure upon said resistor, and means actuated by said actuator to connect said resistor in circuit upon applying initial pressure thereto and removing said resistor "from circuit after the resistance thereof4v been "de- 4. A rheostatic controller comprising in combination a carbon disk resistor, an actui cuit terminals therefor and removing said ator having a pivoted operating lever and a spring to enable said lever to be given a gradual movement and retained in` any intermediate position, and means actuated by said actuator to vary pressure upon said resistor and including a low-tension spring to vary a low pressure upon said resistor and thereby enable a gradual variation in resistance to be obtained throughout a wide upper range and a higher-tension spring to vary a higher pressure upon said resistor and thereby enable a gradual variation in resistance to be obtained throughout a wide continuing lower range.

v5. A rheostatic controller comprising in combination two carbon disk resistors arranged parallel to each other, an actuator having a pivoted operating lever and a spring to enable said lever to be given a gradual movement and retained in any intermediate position, and means aetuated\by said actuator to vary a low pressure upon said resistors by a low-tension spring proportioned to allow said lever to have a wide or substantial movement in varying said low pressure and thereby enable a gradual vari ation in resistance to be obtained throughout a widerange above the normal gradual variationina low resistance obtainable by variation in a highpressure upon said resistors.`

6. A rheostatic controller comprising in combination two carbon Adisk resistors arl ranged parallel to each other, an actuator having a pivoted operating lever and a spring to enable said lever to be given a gradual movement and retained in any intermediate position, means actuated by said actuator to vvary a low pressure' upon said resistors by a'low-tension spring proportioned to allow said lever to have a wide or substantial movement in varying said low pressure and therebyenable a gradual variation in resistance to be obtained throughout a wide range above the normal. gradualvariation in a low resistance obtainable by variation in a high pressure upon said resistors, and means actuated by `said actuator to connect said resistors in circuit in series between eirresistors from circuit after the resistance thereof has been decreased by pressure.

7. A rheostatic controller comprising in combination two carbon disk resistors arranged parallel to each other, an actuator having a pivoted operating lever and a spring to enable said lever to be given a gradual movement and retained in any intermediate position, and means actuated bysaid actua- -tor to vary a low pressure upon said resistors by a fiat low-tension spring having its ends applying pressure to said resistors and proportioned to allow said lever to have a wide or substantial movementin varying said low pressure and thereby enable a gradual variation in resistance to be obtained throughout a wide range above the normal gradual variation in a low resistance obtainable by variation in a high pressure upon saidl resistors.

8. A rheostatic controller comprising in combination two carbon disk resistors arranged parallel to each other, an actuator having a pivoted operating lever and a spring to enable said lever to be given gradual movement and retained i'n any intermediate position, and a flat low-tension spring having each end thereof vary pressure upon a resistor by said actuator deeeting said spring.

9. A rheostatic controller comprising in combination two carbon disk resistors arranged parallel to each other, an actuator having a pivoted operating lever and a spring to enable said lever to be given a gradual movement and retained in any intermediate position, a fiat low-tension spring having each end thereof varypressure upon a resistor by said actuator deiecting said spring, and a supplemental plate arranged behind said lowtension spring to apply a higher pressure to said resistors after said low-tension spring has increased a low pressure .upon said resistors,

l0. A rheostatic controller comprising in combination two carbon disk resistors arranged parallel to each other, an actuator having al pivoted operating lever and a spring to enable said lever to be given a gradual movement and retained in any intermediate position, a flat low-tension spring having each end thereof vary pressure upon a resistor by said actuator deiecting said spring, and a connecting rod arranged between said resistors and .connecting said low-tension spring to said actuator.

.11; A rheostatic controller comprising in combination two carbon disk resistors arranged parallel to each other, an actuator having a pivoted operating lever and a spring to enable said lever to be given a gradual movement and retained in any intermediate position, a flat low-tension spring having each end thereof vary pressure upon a resistor to enable said lever to be given a gradual movement and retained in any intermediate position, a flat low-tension spring actuated by sald actuator to vary a low pressure upon said resistors and roportioned to allow said lever` to have a Wi e or substantial movement in varying said 10W pressure and thereby enable a gradual variation in resistance to be btained throughout a wide upper range, and a flat higher-tension spring actuated by said actuator to vary a higher pressure upon said resistors and thereby enable a gradual variation in resistance to be obtained throughout a wide continuing lower range.

In witness whereof, I have hereunto subscribed my name.

GUSTAV O. WILMS. 

